\documentclass{article}

\usepackage{pgfplots}

\pgfplotsset{compat=1.14}

\begin{document}

\begin{tikzpicture}
	\begin{axis}[colormap name=viridis,colorbar]
	%\tracingmacros=2 \tracingcommands=2
	\addplot3[contour filled={
			levels from colormap={
				of colormap={target pos={-50,0,50}}
			},
		},
	]
	{x^2*y};
	\end{axis}
\end{tikzpicture}
\end{document}

